ACT Reading | Passage Four Practice

The main point of this passage is to:

• 1. illustrate the importance of genetics in the formation of a baby’s brain.

• 1. illustrate the importance of stimulation and experience in the formation of a baby’s brain.

• 1. indicate the great need for conducting further research on babies’ brains.

• 1. compare the latest research on babies’ brains with similar research conducted fifteen years ago.

The main point made in the second, third, and fourth paragraphs (lines 14–52) is that the structure of a baby’s brain:

• 5. is genetically determined before the child is born.

• 5. can be seen through positron-emission tomography.

• 5. can be altered through a process known as pruning.

• 5. is still developing after the child is born.

According to the passage, one thing PET allows neurobiologists to do is:

• 1. observe activity in the frontal cortex of a baby’s brain.

• 1. determine the number of genes involved in the formation of a baby’s brain.

• 1. control the release of neurotransmitters in a baby’s auditory cortex.

• 1. restore microscopic connections in a baby’s brain.

When she compares a baby’s brain to city neighborhoods, the author is most nearly illustrating her point that:

• 5. neurotransmitters are actually brain chemicals.

• 5. regions of the brain are awakened through experience.

• 5. the visual cortex allows a baby to recognize specific images.

• 5. a baby’s brain has about 1,000 trillion synapses.

Which of the following would the author of the passage be LEAST likely to recommend as a way to strengthen the synapses of a baby’s brain?

• 1. Reading to a baby

• 1. Playing peekaboo with a baby

• 1. Teaching a baby with flashcards

• 1. Showing a baby how to distinguish red socks from blue blocks

The last paragraph suggests that the formation of synapses occurs most rapidly:

• 5. during the first two months of a child’s life.

• 5. during the first nine months of a child’s life.

• 5. from the time a child is about six months old until that child is about ten years old.

• 5. from the time a child is about one year old until that child is well into adolescence.

As it is used in line 30, the phrase something innate most nearly means:

• 1. a memory.

• 1. learned behavior.

• 1. physical immaturity.

• 1. an inherited trait.

The fifth paragraph (lines 53–70) suggests that one of the main causes of pruning is:

• 5. a lack of stimulation.

• 5. an insufficient number of genes.

• 5. the use of flashcards.

• 5. the strengthening of synapses.

When the author refers to “entrepreneurs preying on the anxieties of new parents” (lines 60–61), she is most likely suggesting that new parents should:

• 1. give their babies products such as flashcards only if they have examined these products carefully.

• 1. not be deceived by advertising that claims certain products will increase a baby’s intelligence.

• 1. not worry if their babies’ development is slightly behind that suggested by neurobiologists.

• 1. take their pediatrician’s advice before they listen to the advice given by other family members.

The passage states that, in terms of development, the average baby should be able to:

• 5. focus his or her eyes on an object at two months of age.

• 5. develop a “startle” reflex at about two months of age.

• 5. make logical connections between ideas at about four months of age.

• 5. form explicit memories at about nine months of age.